An air bearing conveyor

ABSTRACT

Article handling apparatus including load supporting means in the form of air bearings mounted on decks and actuable to provide a film of air for supporting a load above the surface of the decks. Propulsion means, which may be in the form of conveyor belts, are associated with one or more of the decks and have extended and retracted positions respectively engageable with, and spaced from, a load supported above the surface of the decks on the film of air. The propulsion means may be actuable to an extended position in response to energization of the air bearings so that the path of movement of the load can be determined by energization of a particular group of air bearings, and the direction of movement along the path can then be determined by energization of the propulsion means.

United States Patent Donlon (451 Apr. 4, 1972 Transportation Technology,Inc., Madison Heights, Mich.

[22] Filed: Mar. 5, 1971 [21] Appl.No.: 121,605

[72] Inventor:

[73] Assignee:

Related U.S. Application Data [63] Continuation-impart of Ser. No.778,546, Nov. 25,

1968, abandoned.

Williamson ..214/6 P man, Krass, Perry, Young & Thorpe 3,273,727 9/1966Rogers et al ..2 14/16 8 3,313,367 4/1967 Swedburg ...180/l24 X3,414,076 12/1968 Bertin et a1. 180/124 3,469,887 9/ 1969 Nakahara et al..214/1 AB X 3,273,727 9/1966 Rogers et a1. ..214/l BE PrimaryExaminer-Gerald M. Forlenza Assistant Examiner-R. B. Johnson Attorney-McGlynn. Reising. Milton & Ethington. Adel- [57] ABSTRACT Articlehandling apparatus including load supporting means in the form of airbearings mounted on decks and actuable to provide a film of air forsupporting a load above the surface of the decks. Propulsion means,which may be in the form of conveyor belts, are associated with one ormore of the decks and have extended and retracted positions respectivelyengageable with, and spaced from, a load supported above the surface ofthe decks on the film of air. The propulsion means may be actuable to anextended position in response to energization of the air bearings sothat the path of movement of the load can be determined by energizationof a particular group of air bearings, and the direction of movementalong the path can then be determined by energization of the propulsionmeans.

7 Claims, 5 Drawing Figures Patented April 4, 1972 3,653,485

2 Sheets-Sheet 2 INVENTOR.

mumm AT TOQNEVJ AN AIR BEARING CONVEYOR This application is acontinuation of Ser. No. 778,546 filed Nov. 25, 1968 and now abandoned.

This invention relates generally to article handling apparatus andsystems and is particularly concerned with an article handling apparatusand system for handling freight containers, vehicles and other articlescapable of being supported for substantially friction-free movement on afilm of air provided by air bearings or the like.

With the increase in the volume of freight, severe demands are beingplaced on existing handling and warehousing facilities. In the field ofair freight, for example, extraordinary demands are being placed onground equipment and facilities for the transfer and warehousing of airfreight containers or articles, and existing systems will soon not havethe ability to maintain a continuous and orderly flow of goods. Thereis, therefore a definite need, at air freight terminals particularly,for a handling and storage system for freight containers. Afterunloading from aircraft or ground vehicles, freight containers orpallets are placed in a warehouse where they are either held in storageat selected locations within the warehouse, or are trans-shipped toother aircraft or ground handling vehicles. The type of equipmentcurrently used for this process consists generally of inverted castersmounted in structures laid on the warehouse floor.

Freight handling systems for warehouses at different locations must becapable of meeting the specific demands at the different locations andcapable of operating under different conditions. For example, onewarehouse may require a particular traffic pattern and may be of aparticular size, while a warehouse at another terminal may have smallerfloor space requiring a different traffic pattern and must be capable ofmeeting different demands. Thus, it is desirable to provide a modularstructure for a freight handling system that can be combined in variousarrangements and provide the flexibility necessary to meet the varyingdemands.

In recent years, air bearings have been developed for maintaining a filmof air between a floor or deck and an article such as a pallet in orderto enable omni-directional, friction-free movement of the article overthe deck.

It is therefore an object of this invention to provide an articlehandling system wherein the articles are supported for substantiallyfriction-free horizontal movement when propelled by propulsion devices,such as conveyor belts, normally spaced from the supported articles, butwhich are extendable to engage and propel the article by energization ofair bearings associated with the propulsion devices.

A further object is to provide an article handling system including aplurality of air bearings for supporting articles above the surface of adeck, and propulsion means having extended and retracted positionsrespectively engageable with, and spaced from, articles supported abovethe surface of the deck by the air bearings for selectively propellingloads over the surface of the deck.

Still another object is to provide article handling apparatus includinga plurality of decks with load supporting means associated with each ofthe decks energizable to provide a film of air for supporting a loadabove the surface of the associated deck; and propulsion meansassociated with at least one of the decks having extended and retractedpositions respectively engageable with and spaced from articlessupported above the surface of the decks on the film of air in which theresponse to energization of the load supporting means for the deckportion associated with the propulsion means.

Still another object is to provide an article handling module having aplurality of propulsion devices selectively operable to propel a loadalong its respective path when a plurality of air hearings on eitherside of the propulsion devices for supporting the load above the surfaceof the deck are energized.

Still another object is to provide an article handling module having acenter deck, means defining a plurality of paths of movement eachextending outwardly from the center deck at an angle with respect to theadjacent path of movement, a main deck located between each adjacentpair of the paths and extending from the center portion to the peripheryof the module, a group of air bearings on each of the main deck portionsfor supporting a load above the surface thereof, and a propulsion deviceon each of the paths selectively operable to propel a load along itsrespective path.

A further object is to provide an article handling system for storing,collecting and transporting articles such as palletized freightcontainers wherein the articles can be moved to selected storage areasalong any one or more of a plurality of paths while supportedfrictionfree on a film of air.

Another object is to provide an article handling system having astorage, collection and transporting area for articles such as freightcontainers, pallets and the like having a primary path of movement forthe articles defined in said area and extending in one direction acrossthe area and a plurality of secondary paths extending in differentdirections and connecting the first path with storage or unloading areasspaced from the primary path, with air bearings or the like on each sideof each path for providing a film of air to support the articles, and aplurality of propulsion devices along each path individually actuable topropel an article straddling the respective path and supported on thefilm of air above the decks adjacent thereto a selected distance.

In carrying out the foregoing, and other objects, an article handlingmodule according to the present invention may include a center deck witha plurality of paths of movement defined that extend outwardly from thecenter deck. A main deck is located between each adjacent pair of thepaths and extends from the center deck to the periphery of the module. Agroup of air bearings is located on each main deck for supporting anarticle above the surface thereof, and a propulsion device is located oneach path and is selectively operable to propel a load therealong. Thepropulsion device may be in the form of a conveyor movable between anextended and retracted position so as to selectively engage and propelarticles supported on the air bearings. The conveyor belts have aportion overlying belt supporting air bearings, which, when energized,actuate the belt to its extended position. A plurality of the modulescan be arranged in an article handling system covering an entire areafor the collection, storage and transshipment of articles.

Other objects, advantages and features of the invention will becomeapparent from the following description taken in connection with theaccompanying drawings in which:

FIG. 1 is a perspective view of a portion of a warehouse having anarticle handling system according to the present inventlon;

FIG. 2 is a perspective view of an article handling module according tothe present invention;

FIG. 3 is a partial perspective view of a portion of the module in FIG.2 slightly enlarged;

FIG. 4 is a perspective view of an air bearing membrane suitable for usewith the present invention; and

FIG. 5 is a sectional view taken on lines 5-5 of FIG. 2.

FIG. 2 illustrates an article handling module 10 having a plurality ofdecks l2, l4 and 16 with means 20, 22, 24 associated with each of thedecks energizable to provide a film of air for supporting an articleabove the surface of the decks. Propulsion means 26 is associated withdecks I6 and has extended and retracted positions respectivelyengageable with and spaced from articles supported on the film of airabove the surfaces of the decks. The propulsion means 26 is actuable toan extended position in response to energization of the supporting means24 associated with the propulsion means 26.

Each of the supporting means comprises a group of air bearings 20, 22and 24, and each air bearing is operable to provide support for anarticle when the air bearings are energized with a supply of air. Thepropulsion means comprises a plurality of propulsion devices in the formof conveyor belts 26 each mounted on a different deck 16 andindividually actuable to its extended position in response toenergization of its associated group of air bearings 24. As shown, theseveral propulsion devices are operable to propel an article indifferent directions so that the direction of movement of the article isdetermined by extension of a selected propulsion device 26 uponenergization of its associated group of air bearings 24 when the articleis in position to be engaged by the extended propulsion device.

As pointed out previously, the propulsion devices 26 each comprises aconveyor belt, and each conveyor belt has a portion 27 overlying itsassociated group of air bearings 24 such that flow of air from the airbearings causes extension of portion 27 of the conveyor belt. In FIG. 5,for example, the phantom lines indicate the extended positions of theupper runs 27 of conveyor belts 26a and 26c. When the air bearings 24are de-energized and no air flows therefrom, the overlying portions 27of belts 26 become slack and rest on the inactive air bearings 24 out ofengagement with the articles supported above the surface of decks 12 onthe film of air provided by air bearings 20.

Deck 14 constitutes the center deck of the module 10, and decks 16 arerecessed with respect to the center decks 14. Decks 16 extend outwardlyfrom the center deck 14, and decks 12 constitute main decks between therecessed decks 16, the main decks lying in substantially the same planeas the center deck 14. Thus, an article straddling conveyor belt 26cwill be supported on the air bearings 20 of the main decks 12 on eachside of conveyor 26c. When the air bearings 24 beneath conveyor belt 26care energized, the upper portion 27 of conveyor belt 26c will assume theextended position shown in phantom lines in FIG. to engage the bottomsurface of the article L. The belt 26c can then be actuated to propelthe article L in either direction due to its engagement with the bottomsurface of the article. Assuming that the belt is actuated to propel thearticle toward the left, or toward the center deck 14, the article willcome to rest supported on the film of air provided by the air bearings22 on the center deck 14, in which position it will partially straddleeach of the four belts. If the air bearings 24 beneath belt 26b are thenenergized, belt 26b will be actuated thereby to extend into engagementwith the article, and can then be driven to propel the article away fromthe center deck 14 upon energization of the air bearings located on themain decks 12 on each side of belt 26b. The article will thus bepropelled by belt 26b in a direction at a right angle to the directionof belt 260.

Defined beneath each group of air bearings 20, 22 and 26 are plenumchambers 30, 34 and 32 respectively. Conventional blowers may beemployed in each plenum chamber as indicated at 28 in FIG. 2 forenergizing the air bearings supported on the deck above the respectiveplenum chamber. When the plenum chambers are pressurized by the blowers,air from the plenum chambers passes through openings in the decks inregistry with the air bearings to energize the air bearings, and in thecase of the belt supporting air bearings 24, to extend the belts intoposition to engage and propel articles.

Obviously, other means can be provided for supplying air to energize theair bearings to individually and selectively energize the respectivegroups of bearings associated with each deck. Air can be fed to thebearings by manifolds controlled by solenoid valves, or by ducts from acentrally located source of air, the ducts being individually controlledby dampers or solenoid valves so that operation of a valve will energizea selected group of air bearings.

FIGS. 3 and 4 illustrate the typical construction and mounting of theair bearings. Each of the air bearings 20, 22 and 24 comprises aninflatable membrane 36 mounted on the respective decks l2, 14 or 16(FIG. 4). The membrane 36 has a peripheral flange 38 which is secured byan adhesive or other conventional means to the deck, and a throatportion 40 having apertures 41 formed therein for the escape of air. Anannular inflatable portion 42 extends between the peripheral portion andthroat portion. The throat portion 40 may be in the form of a dischaving apertures 41 formed therein, and normally seats on a raisedportion 46 in the center of an annular recessed portion 50 of itsrespective deck. Openings 44 in the recessed deck portion 50 providepassages for air to flow from the blower or other source to the chamberdefined by the interior of the membrane and the deck. Air flows throughthe openings 44 and air cannot escape from the cavity defined by themembrane except through the openings 41 in the throat portion 40. Hence,the membrane 36 will initially inflate and air will pass from openings41 into the generally frusto-conical cavity 43 defined by the exteriorsurface of the throat disc 40 and annular portion 42. Consequently, whenthe horizontal bottom of an article is disposed over the membrane, thepressurized air flows from cavity 43 over the upper periphery of theannular portion 42 between the upper edge thereof and the opposed bottomsurface of the article and provides a film of air supporting the articleabove the surface of the deck portions in a substantially friction-freemanner. When a membrane is damaged, or becomes worn, it can be removedmerely by breaking the adhesive bond between the deck and peripheralflange 38 and a new one can be adhesively secured in place. Theconstruction of the particular air bearing may be similar to theconstruction of the air cushion device shown in U.S. Pat. No. 3,321,038of Mackie et a].

The conveyors 26 may be driven by a conventional reversible electricmotor as indicated at 52 in FIG. 2. As shown in FIG. 2, the motor 52 isconnected through a belt 54 with a pulley which in turn is drivinglyconnected with the drive roll 56 of conveyor 26c. Conveyor 260 may inturn be drivingly connected with conveyor 26:: so that motor 52 drivesboth conveyors 26a and 26c simultaneously. Conveyors 26d (FIG. 1) and26b may be similarly drivingly connected together. The conveyorillustrated in the drawing is of the endless belt type which extendsaround the drive rolls 56 and idler rolls 60 and passes beneath the deck16 through the plenum chamber 32. When the air bearings 24 beneath theconveyor portions 27 are inactive with no air flowing therefrom, portion27 lies slack over the inactive bearings in spaced relationship to thebottom surface of an article straddling the belt and supported by airbearings 20.

FIG. 1 illustrates a system for handling articles such as flat bottomedfreight containers L or pallets on which containers, vehicles or cratescan be carried on air bearings. FIG. 1 thus illustrates an articlehandling system comprising a storage, collection and transporting areafor articles designated by reference character I... A plurality ofmodules 10a, 10b, 10c, etc. are aligned such that a first or primarypath of movement for the articles is defined in the area extending inthe direction ofconveyors 26d and 26b across the area. Secondary pathsare defined in the areas which extend in the direction of conveyors 26aand 260 for connecting the first path with article storage spacesseparated from the first path. Decks 12 are located on each side of eachpath, and the supporting means in the form of air bearings 20 on decks12 are operable when energized to provide a film of air forfriction-free movement of the articles L over the decks 12 and 14 of themodule. Conveyors 26b and 26d provide propulsion devices along theprimary path, and conveyors 26a and 260 provide propulsion devices alongthe secondary paths.

The first module 1011 in FIG. 1 is provided with a turntable 62 mountedin the center deck 14 for orienting the pallets or articles L as theyare received in the system on module 10a. The turntable may comprise arotatable platform of conventional construction that can be extended andretracted into and out of engagement with the bottom surface of thearticles L. Thus, when an article is unloaded onto module straddlingconveyor belt 26d, the air bearings 20 on each side of conveyor belt 26dare energized to support the article above the associated decks 12.Energization of the air bearings 24 (FIG. 2) beneath conveyor belt 26dextends the upper portion 27 of the belt into engagement with the bottomsurface of the article. The conveyor belt can then be actuated to propelthe article to a position overlying deck 14 and the retracted turntable62. The turntable can then be extended upwardly into engagement with thebottom of the article L and then rotated to orient the article asdesired. The article can then be transferred along the primary path to aselected secondary path, and along the selected secondary path to adesired storage area. The articles are transported along the primarypath by successively extending belts 26d and 26b of module a, belts 26dand 26b of module 10b, and so forth until the intersection between theprimary path and the secondary path leading to the desired storage areais reached. At this juncture, the article is then moved to the left orright of the primary path by the belts 26a and 260.

When the article reaches its destination or storage area, the bearingson the storage module can be de-energized and the article rests on thedecks 12 of the storage module and the collapsed air bearing membranes.The article can be relocated as desired, or returned to the primary pathby first energizing the bearings 20 beneath the article to provide asupport for a moving or stationary article. At this stage, all of theconveyor belts are dead on the storage module containing the article,and all of the bearings 20 may be energized. One of the belts is thenextended to engage the article by actuating the bearings 24therebeneath. The extended belt can then be driven in the desireddirection to propel the article along the path of the belt.

Movement of the articles can be carried out by an operator from thecontrol console 70 in FIG. 1. The operator can selectively energize anyof the groups of air bearings and control the actuation and direction ofthe various conveyor belts to select the path of movement of thearticles. The control console 70 may, for example, have a system mapthereon with propulsion control buttons, and a logic network controllingthe air supplies and belts on a demand basis ahead of an advancingarticle or palletized container with interlocks to prevent collisions.Indicator lights may identify the presence and position of an article ona module surface by means of pressure switches located on the module.

While a specific form of the invention has been illustrated anddescribed in the foregoing specification and accompanying drawings, itshould be understood that the invention is not limited to the exactconstruction shown, but that various alterations in the construction andarrangement of parts, all falling within the scope and spirit of theinvention, will be apparent to those skilled in the art.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. Article handling apparatus comprising: a center deck portion; aplurality of main deck portions; a plurality of recessed deck portionseach being located between a pair of main deck portions; a plurality ofair bearings on each of said main deck portions operable when energizedto support an article in a substantially friction free manner above thesurface of the respective main deck portions; a powered belt conveyormounted on each recessed deck portion having an upper portion overlyingsaid recessed deck portion and a lower portion extending beneath saidrecessed deck portion; at least one air bearing on each recessed deckportion beneath the upper portion of the associated belt conveyor, saidupper portion of said associated belt conveyor having a slack positionspaced beneath the surface of an article supported by the energized airbearings on said main deck portions, said air bearings on said recesseddeck portions each being operable when selectively energized to extendthe upper portion of the belt conveyor associated therewith to anextended position to engage an article straddling said belt conveyor andsupported by the energized air bearings on said main deck portions andpropel the article along the path of said belt conveyor; said centerdeck portion constituting a neutral zone between said main and recesseddeck portions and having orienting means thereon having an active and aninactive condition and operable in the active condition to support anarticle above the surface of said center deck portion and above thesurface of the surrounding main deck portion and permit the article tobe rotated about a vertical axis such that an article propelled ontosaid center deck portion from one direction by one of said beltconveyors can be selectively oriented about a vertical axis uponactivation of said orienting means into a position to be propelled fromsaid center deck portion in a desired direction by any one of said beltconveyors whereby an article located on said center deck portion andstraddling the recessed deck portions radiating from said center deckportion can be propelled from said center deck portion in a selecteddirection by selective energization of the air hearings on the recesseddeck portions; means for supplying air pressure to said air bearings,and means for activating said orienting means on said center deckportions.

2. Article handling apparatus as claimed in claim 1 wherein saidorienting means on said center deck portion comprises a turntableselectively movable in a vertical direction between retracted andextended positions respectively corresponding to the inactive and activeconditions and respectively spaced from and engageable with an articlesupported on the surrounding air bearings on said main deck portions,said turntable being selectively rotatable about a vertical axis.

3. Article handling apparatus as claimed in claim 1 wherein each airbearing comprises an inflatable membrane mounted on the respective deck.

4. Article handling apparatus as claimed in claim 3 wherein saidmembrane includes a peripheral flange secured to the deck; meansdefining a central throat portion for the flow of air from the membrane,and an annular inflatable portion between said peripheral portion andthroat portion.

5. Article handling apparatus as claimed in claim 4 wherein the meansdefining a throat portion comprises a disc with a plurality of aperturesformed therein.

6. Article handling apparatus as claimed in claim 5 further including atleast one opening in the associated deck in registry with the annularinflatable portion of each membrane.

7. Article handling apparatus comprising: a center deck portion; aplurality of main deck portions; a plurality of recessed deck portionsbeing located between a pair of main deck portions; a plurality of airbearings on each of said main deck portions operable when energized tosupport an article in a substantially friction free manner above thesurface of the respective main deck portions; a powered belt conveyormounted on each recessed deck portion having an upper portion overlyingsaid recessed deck portion and a lower portion extending beneath saidrecessed deck portion; at least one air bearing on each recessed deckportion beneath the upper portion of the associated belt conveyor, saidupper portion of said associated belt conveyor having a slack positionspaced beneath the surface of an article supported by the energized airbearings on said main deck portions, said air bearings on said recesseddeck portions each being operable when selectively energized to extendthe upper portion of the belt conveyor associated therewith to anextended position to engage an article straddling said belt conveyor andsupported by the energized air hearings on said main deck portions andpropel the article along the path of said belt conveyor.

1. Article handling apparatus comprising: a center deck portion; aplurality of main deck portions; a plurality of recessed deck portionseach being located between a pair of main deck portions; a plurality ofair bearings on each of said main deck portions operable when energizedto support an article in a substantially friction free manner above thesurface of the respective main deck portions; a powered belt conveyormounted on each recessed deck portion having an upper portion overlyingsaid recessed deck portion and a lower portion extending beneath saidrecessed deck portion; at least one air bearing on each recessed deckportion beneath the upper portion of the associated belt conveyor, saidupper portion of said associated belt conveyor having a slack positionspaced beneath the surface of an article supported by the energized airbearings on said main deck portions, said air bearings on said recesseddeck portions each being operable when selectively energized to extendthe upper portion of the belt conveyor associated therewith to anextended position to engage an article straddling said belt conveyor andsupported by the energized air bearings on said main deck portions andpropel the article along the path of said belt conveyor; said centerdeck portion constituting a neutral zone between said main and recesseddeck portions and having orienting means thereon having an active and aninactive condition and operable in the active condition to support anarticle above the surface of said center deck portion and above thesurface of the surrounding main deck portion and permit the article tobe rotated about a vertical axis such that an article propelled ontosaid center deck portion from one direction by one of said beltconveyors can be selectively oriented about a vertical axis uponactivation of said orienting means into a position to be propelled fromsaid center deck portion in a desired direction by any one of said beltconveyors whereby an article located on said center deck portion andstraddling the recessed deck portions radiating from said center deckportion can be propelled from said center deck portion in a selecteddirection by selective energization of the air bearings on the recesseddeck portions; means for supplying air pressure to said air bearings,and means for activating said orienting means on said center deckportions.
 2. Article handling apparatus as claimed in claim 1 whereinsaid orienting means on said center deck portion comprises a turntableselectively movable in a vertical direction between retracted andextended positions respectively corresponding to the inactive and activeconditions and respectively spaced from and engageable with an articlesupported on the surrounding air bearings on said main deck portions,said turntable being selectively rotatable about a vertical axis. 3.Article handling apparatus as claimed in claim 1 wherein each airbearing comprises an inflatable membrane mounted on the respective deck.4. Article handling apparatus as claimed in claim 3 wherein saidmembrane includes a peripheral flange secured to the deck; meansdefining a central throat portion for the flow of air from the membrane,and an annular inflatable portion between said peripheral portion andthroat portion.
 5. Article handling apparatus as claimed in claim 4wherein the means defining a throat portion comprises a disc with aplurality of apertures formed therein.
 6. Article handling apparatus asclaimed in claim 5 further including at least one opening in theassociated deck in registry with the annular inflatable portion of eachmembrane.
 7. Article handling apparatus comprising: a center deckportion; a plurality of main deck portions; a plurality of recessed deckportions being located between a pair of main deck portions; a pluralityof air bearings on each of said main deck portions operable whenenergized to support an article in a substantially friction free mannerabove the surface of the respective main deck portions; a powered beltconveyor mounted on each recessed deck portion having an upper portionoverlying said recessed deck portion and a lower portion extendingbeneath said recessed deck portion; at least one air bearing on eachrecessed deck portion beneath the upper portion of the associated beltconveyor, said upper portion of said associated belt conveyor having aslack position spaced beneath the surface of an article supported by theenergized air bearings on said main deck portions, said air bearings onsaid recessed deck portions each being operable when selectivelyenergized to extend the upper portion of the belt conveyor associatedtherewith to an extended position to engage an article straddling saidbelt conveyor and supported by the energized air bearings on said maindeck portions and propel the article along the path of said beltconveyor.